Evacuating apparatus
US6375431B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 15, 2000 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Nov 15, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04C28/08
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An evacuating apparatus having a high energy efficiency when the suction side pressure has reached the ultimate pressure or become a certain degree of vacuum, by decreasing the motive power owing to differential pressure. The evacuating apparatus (100) having a roughing vacuum pump (B) and a booster pump (A), each of which is constituted by a screw vacuum pump, wherein the design pumping speed of the roughing vacuum pump (B) is sufficiently smaller than the design pumping speed of the booster pump (A), but adequate to be operable as the roughing vacuum pump, and the number of turns of screw for the booster pump (A) is less than the number of turns of screw for the roughing vacuum pump (B).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.